Conventionally, a cured product obtained by polymerizing and curing a polyallyl ester compound containing multiple allyl ester groups in a molecule is excellent in transparency, heat resistance, electric properties and light resistance, and has been used for optical materials, electronics, artificial marble, decorative laminates and an anti-cracking agent for unsaturated polyester resin. For example, Patent Document 1 (WO 02/33447) (EP 1331494) and Patent Document (JP 2009-197102 A) (U.S. Pat. No. 7,989,563) disclose an optical lens and film using a polyallyl ester compound, Patent Document 3 (JP 2011-22490 A), Patent Document 4 (JP 2008-44357 A) (WO 2008/010588) and Patent Document 5 (JP 2007-299739 A) (WO 2007/117030) disclose a substrate using a polyallyl ester compound, and Patent Document 6 (JP 2010-84008 A) discloses a semiconductor device using a polyallyl ester compound as an adhesive, respectively.
In recent years, there has been a strong demand for higher functionality, downsizing, thinner size and reduction in weight in electronics represented by mobile phones and thin-screen televisions, and studies have been made on substitution of resin members for glass members in optical materials used in the electronics. Heat resistance and transparency near to those of glass, and the characteristics of being lighter in weight and more difficult to break compared to glass are required for resin used as a substitute for glass.
Examples of resin used as a substitute for glass include polyethylene terephthalate (PET) and polycarbonate (PC) in terms of good mechanical strength and excellent transparency. However, the glass transition temperature of the resin is about 70° C. and 140° C., respectively, and it cannot be said that the heat resistance of the resin is sufficient, which has limited their usefulness.
Although the cured product obtained by polymerizing and curing a polyallyl ester compound has higher heat resistance and transparency compared to polyethylene terephthalate (PET) and polycarbonate (PC), it cannot be said that the cured product has sufficient surface hardness depending for use in a front panel of a display unit and the like, and there has been a strong demand for a surface hardness near to that of glass in addition to transparency and heat resistance.